The invention relates generally to vehicular electrical systems and, more particularly, to an apparatus and system for reducing a danger of contact with high voltage present in a vehicle.
Electric vehicles are generally propelled by one or more electric or traction motors powered by electricity, alone or in combination with non-electric propulsion, for example, motive force provided by an internal combustion engine. A source of such electric power may be stored electricity, for example, from a battery bank, electricity generated within the vehicle, and/or electricity received from an external source, such as a trolley in electrical communication with overhead power lines.
In many applications, the designed performance characteristics of an electric vehicle can only be achieved by supplying dangerous high voltages to a drive system. Direct current (DC) voltage may be directly supplied to a DC motor or it may be converted to alternating current (AC) by an inverter circuit that supplies power to an AC motor. A generator of a vehicle may be configured to output either DC or AC voltage. An electric motor may be operated as a generator. Electric power line(s) supplying electricity to a motor of an electric vehicle may be variously arranged in series and/or parallel configurations. An on/off state of such electric power line(s) is typically controlled by one or more controllers.
One or more electric motors of an electric vehicle may be positioned in proximity to a transmission. In such a case, for example, an electric motor may be a cartridge type motor structured to be slidingly removable from a larger housing. For this and other configurations, a worker servicing the vehicle may have difficulty physically accessing the electric power lines, for example within a small engine compartment of a passenger car.
In order to reduce a danger of injury to those in proximity to dangerous high voltage(s) of an electric vehicle, an interlock has been conventionally used to cause a controller to decouple such high voltage(s). The controller may be an electronic control unit powered by a low voltage obtained from a vehicle battery and structured for sending/obtaining low voltage signals to/from various locations of the vehicle. In one common form, a mechanical limit switch is secured within a metal housing so that a protruding portion of a housing cover engages an arm of the limit switch. When the cover is mounted to the housing, the protruding portion engages the arm and the contacts of the limit switch are thereby closed, which causes the controller to enable the provision of electricity to the power lines. When the cover is removed, the protruding portion is pulled away from its engagement with the arm and the contacts of the limit switch are thereby opened, which causes the controller to provide electricity to the power lines. Many different variations exist for removing or applying a high voltage to power lines of an electric vehicle. For example, a connection or disconnection may include, but are not limited to, mechanical, electrical, semiconductor, inductive, and other structures for applying or removing a voltage. A strong supporting structure is required for mounting the limit switch. The wiring to the limit switch may necessitate the use of an additional connector which further reduces available servicing space within an engine compartment. For example, such a supporting structure may be a separate, heavy-duty limit switch housing having an electrical connector formed of heavy gauge metal mounted thereon. Such limit switches and associated installations are costly, heavy, bulky, difficult to install/remove, and are subject to contamination, heat, vibration, and related reliability issues.
With respect to reducing a danger of injury to persons working near dangerous high voltage(s) of an electric vehicle, conventional interlock devices and systems are not optimized for service, repair, or manufacturing of electric vehicles.